Abstract: Monodisperse Cu2O colloidal spheres were produced by a sol-gel reaction process.The sub-micrometer sized Cu2O/Ag composite spheres with core-shell structure were obtained via galvanic replacement method.The as-prepared composites were characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy.Their antibacterial activities against Bacillus subtilis (B.subtilis)and Escherichia coli (E.coli) were also studied.The results show that the average size of Ag nanoparticles (NPs) and Cu2O in the composites is about 7 nm and 150 nm, respectively.Owing to the synergistic action of Cu2O and Ag NPs, the Cu2O/Ag composites show 93; antibacterial activity against E.coli, and the antibacterial rate can reach 95; against B.subtilis.

Key words: Monodisperse Cu2O colloidal spheres were produced by a sol-gel reaction process.The sub-micrometer sized Cu2O/Ag composite spheres with core-shell structure were obtained via galvanic replacement method.The as-prepared composites were characterized with transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and UV-vis spectroscopy.Their antibacterial activities against Bacillus subtilis (B.subtilis)and Escherichia coli (E.coli) were also studied.The results show that the average size of Ag nanoparticles (NPs) and Cu2O in the composites is about 7 nm and 150 nm, respectively.Owing to the synergistic action of Cu2O and Ag NPs, the Cu2O/Ag composites show 93; antibacterial activity against E.coli, and the antibacterial rate can reach 95; against B.subtilis.